In the title coordination polymer, [Pb(C5H2N2O4)(H2O)]n, the PbII atom is seven-coordinated by one N atom and five O atoms from four individual imidazole-4,5-dicarboxylate (HIDC2−) groups and one water molecule. It is interesting to note that the HIDC2− group serves as a bridging ligand to link the PbII atoms into a three-dimensional microporous open-framework.
Supporting information
CCDC reference: 632930
Pb(NO3)2·4H2O (4.03 g, 10 mmol), 1H-imidazole-4,5-dicarboxylic acid (1.54 g, 10 mmol) and NaOH (0.8 g, 20 mmol) were dissolved in an aqueous solution (25 ml). The mixture was sealed in a 50 ml Teflon-lined stainless steel bomb and held at 403 K for 5 d. The bomb was cooled naturally to room temperature, and colourless prismatic crystals were obtained after several days. CHN analysis, calculated for C5H4N2O5Pb: C 15.83, H 1.06, N 7.39%; found: C 15.86, H 1.08, N 7.36%.
H atoms on C and N atoms were placed in calculated positions, with C—H = 0.93 Å and N—H = 0.86 Å, and were refined in the riding-model approximation, with Uiso(H) = 1.2Ueq(C,N). Water H atoms were located in a difference Fourier map and refined with O—H and H···H distance restraints of 0.85 (1) and 1.39 (1) Å, respectively, and with Uiso(H) = 1.5Ueq(O).
Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
poly[aqua-µ-imidazole-4,5-dicarboxylato-lead(II)]
top
Crystal data top
[Pb(C5H2N2O4)(H2O)] | F(000) = 680 |
Mr = 379.30 | Dx = 3.345 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 6840 reflections |
a = 7.0301 (14) Å | θ = 3.2–27.5° |
b = 15.707 (3) Å | µ = 22.39 mm−1 |
c = 6.9680 (14) Å | T = 295 K |
β = 101.77 (3)° | Prism, colourless |
V = 753.2 (3) Å3 | 0.28 × 0.22 × 0.12 mm |
Z = 4 | |
Data collection top
Rigaku R-AXIS RAPID diffractometer | 1717 independent reflections |
Radiation source: fine-focus sealed tube | 1631 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 10.000 pixels mm-1 | θmax = 27.5°, θmin = 3.2° |
ω scans | h = −9→9 |
Absorption correction: numerical (NUMABS; Higashi, 1995) | k = −20→19 |
Tmin = 0.007, Tmax = 0.068 | l = −9→8 |
7289 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.020 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.049 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0251P)2 + 1.5416P] where P = (Fo2 + 2Fc2)/3 |
1717 reflections | (Δ/σ)max = 0.001 |
124 parameters | Δρmax = 0.59 e Å−3 |
3 restraints | Δρmin = −2.08 e Å−3 |
Crystal data top
[Pb(C5H2N2O4)(H2O)] | V = 753.2 (3) Å3 |
Mr = 379.30 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.0301 (14) Å | µ = 22.39 mm−1 |
b = 15.707 (3) Å | T = 295 K |
c = 6.9680 (14) Å | 0.28 × 0.22 × 0.12 mm |
β = 101.77 (3)° | |
Data collection top
Rigaku R-AXIS RAPID diffractometer | 1717 independent reflections |
Absorption correction: numerical (NUMABS; Higashi, 1995) | 1631 reflections with I > 2σ(I) |
Tmin = 0.007, Tmax = 0.068 | Rint = 0.037 |
7289 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.020 | 3 restraints |
wR(F2) = 0.049 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.59 e Å−3 |
1717 reflections | Δρmin = −2.08 e Å−3 |
124 parameters | |
Special details top
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Pb1 | 0.76575 (2) | 0.078709 (8) | 0.51318 (2) | 0.01682 (7) | |
O1W | 0.9412 (5) | 0.0560 (2) | 0.2002 (5) | 0.0322 (7) | |
H1W1 | 0.903 (9) | 0.084 (2) | 0.094 (4) | 0.048* | |
H1W2 | 0.889 (8) | 0.0068 (16) | 0.187 (7) | 0.048* | |
O1 | 0.8664 (4) | 0.22831 (17) | 0.4842 (4) | 0.0228 (6) | |
O2 | 0.8011 (4) | 0.35846 (16) | 0.3635 (4) | 0.0217 (6) | |
O3 | 0.4554 (5) | 0.44080 (18) | 0.1435 (5) | 0.0259 (7) | |
O4 | 0.1632 (5) | 0.4016 (2) | 0.1841 (6) | 0.0371 (8) | |
N1 | 0.5249 (5) | 0.16545 (19) | 0.2821 (5) | 0.0179 (6) | |
N2 | 0.2548 (5) | 0.2321 (2) | 0.1514 (5) | 0.0193 (7) | |
H6 | 0.1347 | 0.2402 | 0.0982 | 0.023* | |
C1 | 0.3387 (6) | 0.1570 (2) | 0.1992 (6) | 0.0205 (8) | |
H1 | 0.2746 | 0.1050 | 0.1772 | 0.025* | |
C2 | 0.7564 (6) | 0.2823 (2) | 0.3817 (5) | 0.0144 (7) | |
C3 | 0.5611 (5) | 0.2516 (2) | 0.2833 (5) | 0.0148 (7) | |
C4 | 0.3932 (6) | 0.2946 (2) | 0.2018 (5) | 0.0153 (7) | |
C5 | 0.3345 (6) | 0.3856 (2) | 0.1756 (6) | 0.0184 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Pb1 | 0.01287 (10) | 0.01455 (10) | 0.02209 (10) | 0.00133 (4) | 0.00136 (7) | 0.00108 (5) |
O1W | 0.038 (2) | 0.0290 (14) | 0.0271 (15) | −0.0037 (15) | −0.0005 (14) | 0.0092 (14) |
O1 | 0.0134 (14) | 0.0198 (12) | 0.0303 (14) | −0.0021 (11) | −0.0072 (12) | 0.0062 (12) |
O2 | 0.0221 (16) | 0.0173 (12) | 0.0241 (13) | −0.0046 (11) | 0.0010 (12) | 0.0019 (11) |
O3 | 0.0222 (17) | 0.0177 (12) | 0.0411 (17) | 0.0043 (12) | 0.0145 (14) | 0.0076 (13) |
O4 | 0.0166 (17) | 0.0226 (14) | 0.073 (3) | 0.0049 (13) | 0.0117 (17) | −0.0041 (16) |
N1 | 0.0139 (17) | 0.0162 (14) | 0.0215 (14) | −0.0012 (12) | −0.0017 (12) | 0.0014 (13) |
N2 | 0.0116 (16) | 0.0198 (15) | 0.0237 (15) | −0.0003 (12) | −0.0035 (13) | 0.0015 (13) |
C1 | 0.015 (2) | 0.0161 (16) | 0.0278 (19) | −0.0040 (15) | −0.0008 (16) | 0.0008 (15) |
C2 | 0.0108 (18) | 0.0171 (16) | 0.0158 (15) | −0.0024 (13) | 0.0038 (14) | −0.0001 (14) |
C3 | 0.0117 (18) | 0.0155 (15) | 0.0169 (15) | 0.0013 (13) | 0.0022 (14) | 0.0015 (14) |
C4 | 0.0139 (19) | 0.0155 (16) | 0.0167 (16) | 0.0016 (14) | 0.0035 (14) | 0.0004 (14) |
C5 | 0.0136 (19) | 0.0196 (17) | 0.0203 (17) | 0.0041 (15) | −0.0002 (15) | 0.0010 (15) |
Geometric parameters (Å, º) top
Pb1—O1 | 2.474 (3) | O3—C5 | 1.266 (5) |
Pb1—N1 | 2.491 (3) | O4—C5 | 1.243 (5) |
Pb1—O3i | 2.547 (3) | N1—C1 | 1.325 (5) |
Pb1—O2i | 2.598 (3) | N1—C3 | 1.377 (4) |
Pb1—O1W | 2.739 (4) | N2—C1 | 1.331 (5) |
Pb1—O3ii | 2.758 (3) | N2—C4 | 1.376 (5) |
Pb1—O4iii | 2.822 (3) | N2—H6 | 0.8600 |
O1W—H1W1 | 0.86 (3) | C1—H1 | 0.9300 |
O1W—H1W2 | 0.85 (3) | C2—C3 | 1.484 (5) |
O1—C2 | 1.266 (5) | C3—C4 | 1.378 (5) |
O2—C2 | 1.250 (4) | C4—C5 | 1.489 (5) |
| | | |
O1—Pb1—N1 | 66.16 (10) | C5—O3—Pb1iv | 129.5 (3) |
O1—Pb1—O3i | 115.05 (10) | C5—O3—Pb1v | 105.3 (2) |
N1—Pb1—O3i | 77.14 (11) | Pb1iv—O3—Pb1v | 114.09 (11) |
O1—Pb1—O2i | 75.03 (9) | C1—N1—C3 | 105.4 (3) |
N1—Pb1—O2i | 108.78 (10) | C1—N1—Pb1 | 135.1 (2) |
O3i—Pb1—O2i | 68.63 (10) | C3—N1—Pb1 | 115.7 (2) |
O1—Pb1—O1W | 82.87 (10) | C1—N2—C4 | 108.3 (3) |
N1—Pb1—O1W | 85.04 (10) | C1—N2—H6 | 125.8 |
O3i—Pb1—O1W | 145.67 (11) | C4—N2—H6 | 125.8 |
O2i—Pb1—O1W | 145.63 (10) | N1—C1—N2 | 111.6 (3) |
O1—Pb1—O3ii | 149.44 (10) | N1—C1—H1 | 124.2 |
N1—Pb1—O3ii | 85.40 (10) | N2—C1—H1 | 124.2 |
O3i—Pb1—O3ii | 65.91 (11) | O2—C2—O1 | 124.1 (4) |
O2i—Pb1—O3ii | 127.48 (9) | O2—C2—C3 | 119.5 (3) |
O1W—Pb1—O3ii | 83.79 (9) | O1—C2—C3 | 116.4 (3) |
O1w—Pb1—O4iii | 77.42 (10) | N1—C3—C4 | 109.7 (3) |
O1—Pb1—O4iii | 69.82 (10) | N1—C3—C2 | 118.3 (3) |
N1—Pb1—O4iii | 134.22 (10) | C4—C3—C2 | 131.7 (3) |
O2i—Pb1—O4iii | 70.42 (10) | N2—C4—C3 | 104.9 (3) |
O3i—Pb1—O4iii | 135.22 (10) | N2—C4—C5 | 119.3 (3) |
O3ii—Pb1—O4iii | 133.12 (10) | C3—C4—C5 | 135.6 (4) |
Pb1—O1W—H1W1 | 121 (4) | O4—C5—O3 | 124.2 (4) |
Pb1—O1W—H1W2 | 87 (4) | O4—C5—C4 | 115.8 (4) |
C2—O1—Pb1 | 122.0 (2) | O3—C5—C4 | 120.0 (4) |
C2—O2—Pb1iv | 118.7 (2) | H1W1—O1W—H1W2 | 109 (4) |
| | | |
N1—Pb1—O1—C2 | 4.1 (3) | C1—N1—C3—C4 | 0.6 (4) |
O3i—Pb1—O1—C2 | −57.5 (3) | Pb1—N1—C3—C4 | −160.7 (2) |
O2i—Pb1—O1—C2 | −114.8 (3) | C1—N1—C3—C2 | 175.5 (3) |
O1W—Pb1—O1—C2 | 91.8 (3) | Pb1—N1—C3—C2 | 14.2 (4) |
O3ii—Pb1—O1—C2 | 27.0 (4) | O2—C2—C3—N1 | 170.9 (3) |
O1—Pb1—N1—C1 | −163.4 (4) | O1—C2—C3—N1 | −10.7 (5) |
O3i—Pb1—N1—C1 | −38.2 (4) | O2—C2—C3—C4 | −15.6 (6) |
O2i—Pb1—N1—C1 | −100.0 (4) | O1—C2—C3—C4 | 162.8 (4) |
O1W—Pb1—N1—C1 | 112.2 (4) | C1—N2—C4—C3 | −0.7 (4) |
O3ii—Pb1—N1—C1 | 28.1 (4) | C1—N2—C4—C5 | −176.1 (3) |
O1—Pb1—N1—C3 | −9.3 (2) | N1—C3—C4—N2 | 0.0 (4) |
O3i—Pb1—N1—C3 | 115.9 (3) | C2—C3—C4—N2 | −173.9 (4) |
O2i—Pb1—N1—C3 | 54.1 (3) | N1—C3—C4—C5 | 174.3 (4) |
O1W—Pb1—N1—C3 | −93.7 (3) | C2—C3—C4—C5 | 0.4 (7) |
O3ii—Pb1—N1—C3 | −177.8 (3) | Pb1iv—O3—C5—O4 | −158.1 (3) |
C3—N1—C1—N2 | −1.1 (4) | Pb1v—O3—C5—O4 | −17.5 (5) |
Pb1—N1—C1—N2 | 154.8 (3) | Pb1iv—O3—C5—C4 | 20.6 (5) |
C4—N2—C1—N1 | 1.1 (5) | Pb1v—O3—C5—C4 | 161.2 (3) |
Pb1iv—O2—C2—O1 | 127.9 (3) | N2—C4—C5—O4 | 27.2 (5) |
Pb1iv—O2—C2—C3 | −53.9 (4) | C3—C4—C5—O4 | −146.4 (5) |
Pb1—O1—C2—O2 | 179.8 (3) | N2—C4—C5—O3 | −151.6 (4) |
Pb1—O1—C2—C3 | 1.5 (5) | C3—C4—C5—O3 | 34.8 (7) |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x+1, −y+1/2, z+1/2; (iv) x, −y+1/2, z−1/2; (v) −x+1, y+1/2, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1W1···O2iv | 0.86 (3) | 1.86 (3) | 2.708 (4) | 176 (6) |
O1W—H1W2···O4ii | 0.85 (3) | 1.95 (3) | 2.705 (5) | 147 (4) |
N2—H6···O1vi | 0.86 | 1.95 | 2.811 (4) | 174 |
Symmetry codes: (ii) −x+1, y−1/2, −z+1/2; (iv) x, −y+1/2, z−1/2; (vi) x−1, −y+1/2, z−1/2. |
Experimental details
Crystal data |
Chemical formula | [Pb(C5H2N2O4)(H2O)] |
Mr | 379.30 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 295 |
a, b, c (Å) | 7.0301 (14), 15.707 (3), 6.9680 (14) |
β (°) | 101.77 (3) |
V (Å3) | 753.2 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 22.39 |
Crystal size (mm) | 0.28 × 0.22 × 0.12 |
|
Data collection |
Diffractometer | Rigaku R-AXIS RAPID diffractometer |
Absorption correction | Numerical (NUMABS; Higashi, 1995) |
Tmin, Tmax | 0.007, 0.068 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7289, 1717, 1631 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.020, 0.049, 1.00 |
No. of reflections | 1717 |
No. of parameters | 124 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.59, −2.08 |
Selected bond lengths (Å) topPb1—O1 | 2.474 (3) | Pb1—O1W | 2.739 (4) |
Pb1—N1 | 2.491 (3) | Pb1—O3ii | 2.758 (3) |
Pb1—O3i | 2.547 (3) | Pb1—O4iii | 2.822 (3) |
Pb1—O2i | 2.598 (3) | | |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x+1, −y+1/2, z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1W1···O2iv | 0.86 (3) | 1.86 (3) | 2.708 (4) | 176 (6) |
O1W—H1W2···O4ii | 0.85 (3) | 1.95 (3) | 2.705 (5) | 147 (4) |
N2—H6···O1v | 0.86 | 1.95 | 2.811 (4) | 173.8 |
Symmetry codes: (ii) −x+1, y−1/2, −z+1/2; (iv) x, −y+1/2, z−1/2; (v) x−1, −y+1/2, z−1/2. |
There has been considerable interest in the design and synthesis of metal–organic complexes during recent decades (Erxleben 2003). The structures and properties of such complexes depend on the coordination habits and geometric preferences of both metal ions and bridging ligands, as well as on the influence of weaker non-covalent interactions such as hydrogen bonding. In investigations of coordination polymers that address the use of bridging multidentate ligands, the anion of 1H-imidazole-4,5-dicarboxylic acid (H3IDC) exemplifies a ligand that is used in the formation of supramolecular complexes. This acid can be successively deprotonated to furnish H2IDC−, HIDC2− and IDC3− anions, these anions giving rise to a wide range of supramolecular architectures. To our knowledge, some transition metal complexes with one-dimensional chain structures of Mn, Cu and Cd complexes (Zhang et al., 2004; Gao, Gu et al., 2004; Gao, Liu et al., 2004), two-dimensional layer structures of Mn and Fe complexes (Gao et al., 2005; Xu et al., 2004) and a three-dimensional Mn complex (Zhang et al., 2006) have been reported to date. Compared with the extensively investigated transition metal cordination polymers, it is surprising to see the relatively small number of main group metal coordination polymers. Recently,we have reported the structure of a mononuclear calcium complex (Gao, Zhang et al., 2004), and a two-dimensional brick-like layer barium coordination polymer (Zhang et al., 2005). However, no three-dimensional crystal structure of a main group metal coordination polymer constructed using this acid has yet been reported. We obtained the title novel three-dimensional lead(II) coordination polymer, [Pb(HIDC)(H2O)]n, (I), and its synthesis and crystal structure are reported here.
As shown in Fig. 1, the asymmetric building unit of complex (I) comprises one PbII atom, one HIDC2− dianion and one coordinated water molecule. Each PbII atom is seven-coordinated by one N atom of an HIDC2− anion, with a Pb—N distance of 2.491 (3) Å, five O atoms from four individual HIDC2− anions, with Pb—O distances in the range 2.474 (3)–2.822 (3) Å, and one water molecule, with a Pb—O distance of 2.739 (4) Å (Table 1). The PbII—O4iii [symmetry code: (iii) x + 1, −y + 1/2, z + 1/2] distance of 2.822 (3) Å is considerably longer, but lies within the range found for PbII—O bond distances in many similar PbII coordination polymers; for example, Morsali & Mahjoub (2004) reported a Pb—O range of 2.542 (10)–2.975 (9) Å.
It is interesting to note that each HIDC2− anion serves as a bridging ligand to link four PbII atoms into a three-dimensional microporous structure. The HIDC2− dianion in (I) shows four different coordination modes. Firstly, it binds to the Pb1 atom in an N,O-bidentate coordination mode through imidazole atom N1 and carboxyl atom O1, forming a five-membered chelate ring. Secondly, it coordinates to atom Pb1A [symmetry code: (A) x, −y + 1/2, z − 1/2] in an O,O-bidentate coordination mode through two carboxyl atoms, O2 and O3, generating a seven-membered chelate ring with an envelope-like conformation. Thirdly, it bridges atoms Pb1A and Pb1B [symmetry code: (B) −x + 1, y + 1/2, −z + 1/2] through carboxyl atom O3. In this case, a centrosymmetric four-membered (Pb/O/Pb/O) loop is formed, with a Pb···Pb distance of 4.1523 (9) Å. Fourthly, it coordinates to atom Pb1C [symmetry code: (C) x − 1, −y + 1/2, z − 1/2] in a monodentate coordination mode through carboxyl atom O4. Furthermore, four such HIDC2− ligands connect four PbII centres, generating a macrocyclic ring structure, with adjacent PbII···PbII distances of 6.4103 (10) and 9.1379 (16) Å (Fig. 2). As a consequence of these H2IDC− bridges, as well as the hydrogen bonds in which all active H atoms in the structure are involved (Table 2), polymer (I) presents an extended three-dimensional microporous open-framework.